parafollicular cells


parafollicular cells
ovoid cells with an irregular nucleus and many brown or black cytoplasmic granules, located in the follicular epithelium and interfollicular spaces along with the principal cells of the thyroid follicles, in the follicular epithelium and interfollicular spaces, and which elaborate calcitonin. They arise during embryonic life from the fifth pharyngeal pouches and are incorporated in the thyroid gland in mammals, but form discrete epithelial cell masses (ultimobranchial bodies) in submammalian vertebrates. Called also C c's and light c's.

Medical dictionary. 2011.